In the future, airless tires may become a popular trend in the selection of materials for self-driving cars

Drivers of the future may have to go to a printing factory rather than a mechanic to buy new tires, as Michelin predicts that airless tires will replace pneumatic tires on passenger cars by 2024.

Uptis (Unique Puncture-Proof Tire System) prototype partly made using a 3D printer (improved version, see above). Uptis promises to eliminate blowouts, punctures and wear caused by over- or under-inflated tires. Michelin is working with General Motors to trial and improve it on the Bolt self-driving car in the United States.

Michelin has been developing airless tires since 2005, but early models left a lot to be desired in terms of speed performance. The picture below shows the first time an airless tire prototype was installed and tested on a road vehicle.

Airless tires simply need to be reprinted

In creating Uptis, Michelin took an aluminum wheel assembly and wrapped it with a composite rubber with high-strength resin embedded in fiberglass. The rubber tread layer covers the part of the tire that contacts the road and can be replaced at any location through 3D reprinting. This airless tire is environmentally friendly and requires less rubber to create the tread layer than traditional all-wheel tires. Due to the new materials and structural improvements, the airless tire can not only withstand the weight of the car, but also perform well at speed.

3D printing technology can provide tread designs that suit user needs based on changes in seasons and user requirements.

Adjusting airless tire design

Bridgestone released the second generation of airless tires as early as 2013, but it is still a long way from commercial application. In addition to improving weight distribution, the unique spoke design leaves the sides uncovered, so the spokes must be adjusted to prevent debris from getting between the spokes.

Where airless tires score the most is that they are considered safer because they cannot burst, which eliminates the need to change a flat tire on a busy road or dangerous highway. There is also no need for a spare tire, which frees up space in the car's trunk and reduces the overall weight of the car, which equates to better overall power economy. In addition, about 90% of the energy loss caused by tire rolling resistance comes from the repeated changes in the shape of the tire as it rolls. By simplifying the tire structure, the energy loss of these "airless tires" can be minimized, helping to reduce CO2 emissions.

Airless tires and autonomous driving

Airless tires are particularly well suited for autonomous vehicles that require near-zero maintenance to maximize their operational capabilities. To this end, Goodyear has developed a non-pneumatic (airless) tire - NPT - and wheel assembly to support autonomous vehicle transportation, which is being tested in Jacksonville, USA. These tires have been installed on the Olli 8-passenger autonomous shuttle bus.

Goodyear's "airless tire" is installed on the Olli 8-passenger automatic shuttle bus

The predecessor of airless tires includes zero-pressure tires (run-flat tires), which have been installed as standard on many luxury car brands such as BMW in recent years. These tires are automatically sealed in the event of a puncture and can be safely driven 50 miles to a repair shop. However, due to the inflexible tire wall, the tires are expensive and reduce ride comfort.

Additionally, Bridgestone announced it is developing an "airless," or non-pneumatic, tire for the passenger car market. Prototypes are still in development.

Bridgestone airless tire technology uses a unique spoke structure designed to support the weight of the vehicle

In 2013, Bridgestone unveiled its second-generation airless concept non-pneumatic tire, which features improved load-bearing capacity, environmentally friendly design, and driving performance. However, before airless tires can be made available to consumers, development and improvements are needed. Finding a way to avoid getting debris caught within the spokes, as well as developing the best way to evenly distribute weight and consistently transfer loads. For these reasons, many believe that airless tires are still a decade or so away from being available. Nonetheless, to keep up with the continued development of the automotive industry, airless tires will also be a trend that consumers and the automotive industry choose.

The future of airless tires

Future tires, including airless tires, will also communicate with vehicles and drivers/fleet managers by providing information about tire usage history and road conditions. This is one of the important reasons why airless tires are chosen for future autonomous driving. Tire manufacturers are also actively launching tires equipped with RFID or radio frequency identification tags to meet the needs of autonomous driving development.